Alignak architecture allows the administrator to have a unique point of administration with numerous schedulers, pollers, reactionners, brokers and receivers.

Hosts are dispatched with their own services to schedulers. The satellites daemons (pollers/reactionners/brokers) get and execute jobs from their schedulers. Everyone is happy! Or almost everyone…

Think about an administrator who has a distributed architecture around the world. With the current Alignak architecture the administrator can have a couple scheduler/poller daemons in Europe and another one set in Asia, but he cannot “tag” hosts in Asia to be checked by the asian scheduler. Trying to check an asian server with an european scheduler can be very sub-optimal, read very sloooow.

The hosts are dispatched to all schedulers and satellites so the administrator cannot be sure that asian hosts will be checked by the asian monitoring servers.

Alignak provides a way to manage different geographic or organizational sites.

Make sure to understand when to use realms and when to use poller_tags.

For some cases poller_tag functionality could also be done using Realms. The question you need to ask yourself: is a poller_tag “enough”, or do you need to fully segregate the scheduler level and use Realms. In realms, schedulers do not communicate with schedulers from other Realms.

In the previous samples, if you put numerous brokers into the realm, each scheduler will have only one
broker at the same time. It is also impossible to have a common Broker in All, and one brokers in each sub-realms.

You can activate multi-brokers features with a realm parameter, the broker_complete_links option (0 by default).

You will have to enable this option in ALL your realms! For example:

definerealm{realm_nameEuropebroker_complete_links1}

This will enable the fact that each scheduler will be linked with each brokers. This will make it possible to have dedicated brokers in a same realm; each one for its specific stuff.

It will also make it possible to have a common Broker in “All”, and one broker in each of its sub-realms (Europe, US and Asia).

Of course the sub-brokers will only see the data from their realms, and the sub-realms (like Paris for Europe for example).